FIG. 1 shows a conventional clamping device generally available in the markets. The conventional clamping device includes a transmission mechanism in which an operating handle A is pivotally turned to incline a push member E behind the operating handle A. When the push member E is inclined, an opening B thereof engaging with a scaled rod D of the clamping device also inclines to firmly contact with, press against, and push the scaled rod D, which is fixedly connected at a distal end to a movable jaw C of the clamping device, so that the scaled rod D, and accordingly the movable jaw C, are linearly moved.
A disadvantage of the above-described transmission mechanism for the conventional clamping device is that the movement of the scaled rod D and the movable jaw C is achieved completely through pressing and pushing the inclined opening B against the scaled rod D. When the clamping device is subjected to relatively large load, a user has to hold and operate operating handle A with increased efforts. Moreover, the operating handle is made of a relatively rigid material that tends to cause a tired and sore hand after being operated over a long period of time.
It is therefore tried by the inventor to develop a clamping device having an improved transmission mechanism to eliminate the above-mentioned drawbacks existed in the conventional clamping device.